Question

In trying to built a object with a inner propriety in the constructor function that keeps the array with all the objects created with the same constructor.

I’m thinking that the best way would be with a closure on object initialization and this is how I try to solve this:

    function myObject (name){
        this.name=name;
        this.allInstances = [];
        }

    myObject.ptototype = {

        init : function(){
            return function(){this.allInstances.push(this.name)};
            }(),
        }   

    object1 = new myObject("object1");
    object2 = new myObject("object2");
    console.log(object1.allInstances); // should print ["object1", "object2"]

Does anyone know how to achieve that ? Is that even possible ?
I’m specifically trying to get a solution which uses only function constructor and prototype to achieve that.

I know how to solve that by pushing the proprieties to an external array, like:

    var allInstances = [];
    function myObject (name){
        this.name=name;
        allInstances.push(this.name);
        }
    console.log(allInstances)

Answer 1

Place the Array as a property on the prototype, and it will be shared among all instances:

function myObject(name) {
    this.name = name;
    this.allInstances.push( this.name );
}

myObject.prototype.allInstances = [];

object1 = new myObject("object1");
object2 = new myObject("object2");

console.log(object1.allInstances); // ["object1", "object2"]

Or if you want the Array to be more protected, use a module pattern, and include a function on the prototype to return the Array.

var myObject = (function() {
    var allInstances = [];

    function func(name) {
        this.name = name;
        allInstances.push( this.name );
    }

    func.prototype.getAllInstances = function() { return allInstances; };

    return func;
})();

object1 = new myObject("object1");
object2 = new myObject("object2");

console.log(object1.getAllInstances()); // ["object1", "object2"]